Oil-in-water emulsion for vat color printing



Patented May 20, 1952 T QFFICE OIL-IN-WATER EMULSION FOR VAT COLORPRINTING Joseph L. Borstelmann and Frederick Fordem- Walt, Bound Brook,N. 3., assignors to American Cyanamid Company, New York, N. Y., acorporation of Maine No Drawing. Application September 8, 1949, SerialNo. 114,694

4' Claims.

This invention relates to a novel composition for printing with vatdyestuffs, to the printing with such compositions, and to the productsso produced. In particular, the invention is concerned with a novel typeof textile printing paste. More specifically, it deals with such pastescon taining, as a thickener, an oil-in-water emulsion.

Use of printing color-paste containing dyes, particularly in printingoperations using vat dyes, is sufficiently well known so that theprocedure has become almost standardized. The actual color source may beeither a dye paste or a dye powder. In addition to the real color, a dyepaste usually contains agents to prevent drying out, settling, and/ orfreezing. Dye powders, not being subject to these difficulties, do notrequire these agents, but they usually contain agents, or are soprocessed, as to promote dispersibility.

In either case, the dye paste or dye powder must be made up into aprinting paste. In so doing, it is customary to admix the real colorwith a suitable thickener to form a paste which is suitable forapplication. In the past, this thickener has usually consisted of a gumand/or starch dispersion.

In the case of vat dyestuffs, it is further necessary to add a reducingagent, and usually, also, an alkali. Because the color yield fromprinting color pastes often decreases rapidly as the paste ages afterbeing made up, these printing color pastes are usually prepared by thefabric finishers just before they are to be used.

The printing color pastes, however compounded, are then applied totextile, paper, or other fabric materials for decorative or protectivepurposes. The printed pieces are dried, aged in a steam ager, treatedwith an oxidizing agent, rinsed, and finally dried. Usually, inprocessing textiles, the printed fabric also is soaped at or near theboil with about a 0.1% soap solution; and again rinsed before the finaldrying operation.

As has been outlined above, the conventional practice has become almoststandardized in its use of a thickener, or carrier," in preparing aprinting paste which contains the dye paste or dye powder. In fact,these thickeners or carriers have themselves become substantiallystandardized in the form of starch-gum compositions which do not varygreatly in composition, wherever or however used.

In spite of the almost universal adoption of such starch-gum carriers,their use has a number of drawbacks. For example, they reqiure thedeposition on the fabric of a large amount of material. It is thereforenecessary for the color to travel through a greater mass of paste thandesirable to reach the fabric surfaces. Being starches and gums, theyalter the hand of the material before finishing and must be removed insubsequent operations. Even more troublesome, the color yields are notalways as good as might be desired. Particularly is this latter true inthe background or blotch section of over-all prints.

There is, therefore, an existing demand for an improved method ofpreparing and using printing paste compositions. They should not besubject to the outlined drawbacks above, which are inherent in the useof conventional starch-gum thickeners or carriers. It is, therefore, aprincipal object of the present invention to develop such compositionsand devise methods for their use.

Surprisingly, compositions fulfilling the objects of this invention havebeen successfully prepared without the use of any starch-gumcomposition. This was quite unexpected in view of the fact that insuccessful printing with vat dyestuffs, it is necessary for the paste tocontain various electrolytes. In general, this result is accomplished bysubstituting for the usual carrier of the art, not a paste but anemulsion of the oil-in-water yp Oil-in-water emulsions, as prepared forthe purposes of the present invention, can be made to contain all theingredients required for successful vat printing. It is a significantdevelopment that such emulsions are stable, despite their containing thehigh electrolyte content required for vat printing.

The exact technique for securing a suitable emulsion may vary. The outerphase may contain hydrophilic materials in solution to withstand thepresence of the high salts content. It may contain one or moresurface-active agents with-out thickeners. The various proportions, andthe sequence followed in the addition of the components to theemulsions, may be varied. Preferably, however, the emulsion will containfrom about 15-60% of the internal oil phase. This internal phase servesprimarily only to body the emulsion, i. e., to provide printingconsistency.

In a preferred method of utilizing the invention, an oil-in-wateremulsion is prepared as a clear vat carrier. It contatins all thechemicals commonly present in the conventional starch-gum vat-printingclear or carrier paste. It is used in application exactly'as are thestarch clears. The color may be present when the emulsion is formed, ifso desired. The final colored 3 emulsion, in any case, is printed on thefabric, and the print then finished, as in the current trade practiceusing a conventional clear.

The internal oil phase, serving primarily to body the emulsion, maycomprise a variety of water-insoluble nonsaponifiable oil's.Hydrocarbons, particularly the more fluid petroleum fractions, arepreferred because of their cost,- availability, and relatively highvolatility. The internal oil phase may be a single aliphatic hidrocarbonor mixtures thereof or with aromatics. An upper boiling range of 300400C. is satisfactory. Preferably, but notneces'sa'rily', the oil ormixtures should have a low viscosity, 1. e.,.five centipoises or lessand a distillation range of 100-300 C. The amount of oil or oil mixtureused will depend on the requirements of the printing paste in which itis incorporated, i. a, the surface to be printed, nature of the pattern,and the like. For a shallow, fine-patterned roll, a printing-pasteviscosity of poises or even less may be desirable. on the other'ha-nd',conditions may be encounteredin which a sti-fipaste of 100 poises ormore may be needed. A viscosity of about 20-60 poises will cover mostrequirements. Viscosity, as discussed herein, is determined on aBrookfield Syncho-letric viscosimeter. I

In addition to these materials, required in and forming the oil-in-wateremulsion as such, there are certain other ingredients required forsuccessful printing of the vat dyestuffs themselves. In standardizedpractice, these will include, for example, an alkali or alkalinematerial, and a reducing agent. In addition, there may be dispersingagents, which are purposely incorporated, or become incorporated throughtheir presence in the dye paste or dye powder, which is used to make upthe printing paste.

For example, it is customary to use, as the alkaline material, sodiumcarbonate and/or potassium carbonate. Ordinarily, both are used;- I-hesebeing soluble in water, they may be added at any point in thepreparation of the'emulsion. In the same way, the customary reducingagent is sodium formaldehyde sulfoxylateor a chemical equivalent. Thistoo may be added at'any stage in the formation of the emulsion. If aprinting assistant, such as glycerin and the like, is" desired, it toomay be added as and when necessary.

Preparation and use of emulsions in the common practice of the presentinvention will be more fully illustrated in conjunction with thefollowing examples. These examples are'intended' as illustrative only.Unless otherwise noted, all parts are by Weight.

Example 1 125 parts of a hydrocarbon solvent (distillation range135'-1"I5 C. and containing approximately 92% of aromatics) isemulsified by means of, an homogenizer into 60'parts of a mixtureconsisting of 50 parts of a 7.5% aqueousdispersion of the vat dyestufi6,6-dichloro-4,4'-dimethyl-bis-tliionaphthene indigo (which dyestuff hadbeen pre-- viou'sly deflocculated in the presence of 1% of disodiumdisulfo dinaphthyl methane) and 10 parts of a 40% aqueous solution ofsodium lignin sulfonate. Into this resultant emulsion is mixed 200 partsof a slurry consisting of 22.5 parts'of anhydrous sodium carbonate, 22.5parts of armydrous potassium carbonate, 35 parts of sodium formaldehydesulf'oxylate, 30 parts of 'glyc'erine', and 90 parts water. Finally anadditional 125' parts of the same hydrocarbon-solvent isemmsified intothe system.

The above procedure produces a well-bodied, smooth, pink-colored O/Wemulsion. Prints made from this color emulsion on bleached 80 x 80cotton cloth are bright, strong, and welldefined. When finally aged,oxidized, soaped, and dried, they compare favorably with similarlyfinished prints made at the same color concentration, using aconventional starch thickener M the vat color carrier.

Example 2 200 parts ofa hydrocarbon solvent (distillation range 135-175C. and containing approximately 92% or aromatics) is emulsified by meansof an Eppenbach homogenizer into 100 parts of a 20% aqueous solution ofsodium lignin sulfonate. Into thev resultant emulsion is stirred 400parts of a slurry consisting of parts of anhydrous potascarbonate, 45parts of anhydrous sodium carbonate, 70 parts of sodium formaldehydesulfoxylate, parts glycerine, and 180 parts of water. Finally 300 partsmore of the above-mentionedliydr'ocarbon solvent is emulsified into thesystem in like manner.- A well-bodied, smooth, tan colored oil-iri-wateremulsion clear results from this procedure;

A vat color printing emulsion is then prepared by stirring 10 parts ofan aqueous dispersion of the Val; dystufli'6,6dichlor0-4,4'-dimethylbisthionaphthene indigo (previously thoroughlydefloceulated in the presence of 1% disodium disulfo dinaphtliylmethane) and containing approximately 15% real dye, into 90 parts of theabove mentioned oil-in-water emulsion clear.

The resulting color emulsion is machine-printed from an intaglioengraved copper roll onto bleached 80 -x 80'cotton cloth and onto spunrayon cloth. The resulting prints, when dried, steamaged, oxidized,soape'd, and ironed dry, are found to be bright and strong, and to haveas sharp a design as prints made at the same color concentration using aconventional starch printing thickener as the carrier for thedeflocculated color dispersion.

Example 3 569'parts of a hydrocarbon solvent (distillation range 135-175C. and containing approximately 92% aromatics) are emulsified by meansof an Eppe'nbach homogenizer into a mix consisting of 38" parts ofanhydrous potassium carbonate, 59 parts of sodium formaldehydesulfoxylate, 51 parts of 'glycerine, 3.4 parts of sodium ligninsulfonat-e, and 247 parts of water. A smooth, light colored oil-in-wateremulsion results.

A- vat color printing emulsion is prepared by stirring? parts of acommercial vat dye paste, containing approximately 15% of the vatdyestufl' 6,6" dichloro 4,4 dimethyl bis thionaphthene indigo into 90parts of the abovemeritioned'oil-in-water emulsion.

When printed on x 80 bleached cotton cloth and finished in theconventional manner, this printing color emulsion gives clear sharpprints whichare brighter and stronger in color value than prints-made.at the same dye strength using a conventional starch thickener as thevat dye paste carrier.

Example 4 10 parts of a commercial vat dye paste, containingapproximately 15% of the vat dyestuff of prototype No; 117, were stirredinto parts of theemulsion. clear described in Example 3. Cotton:printsmade from this vat color printing strong.

Example An oil-in-water emulsion is prepared by emulsifying 480 parts ofa hydrocarbon solvent (distillation range 135-175 C. containing 92% ofaromatics) into an aqueous mix consisting of 4 parts sodium ligninsulfonate, 6 parts of a medium viscosity grade carboxymethyl cellulose,41 parts of anhydrous sodium carbonate, 41 parts of anhydrous potassiumcarbonate, 64 parts of sodium formaldehyde sulfoxylate, 55 parts ofglycerine and 319 parts of water. An Eppenbach highspeed homogenizer isused as the mechanism for producing the emulsion. The resulting productis a creamy white, smooth, well-bodied oil-in-water emulsion. grams ofthe commercial vat dye paste containing approximately of the vatdyestufi 6,6 dichloro-4,4-dimethyl bis thionaphthene indigo, are stirredinto 90 parts of the emulsion clear prepared above. When the resultingcolor emulsion is printed on cotton cloth, the finished prints are foundto be as strong and as clear as prints prepared at the same dyeconcentration using a conventional starch or gum thickener.

Example 6 An oil-in-water emulsion is prepared as di-. rected in Example5 except that 1 part of sodium alginate is substituted for thecarboxymethyl cellulose. A well-bodied creamy oil-in-water emulsion isformed by this procedure. 10 parts of a commercial vat dye paste,containing approximately 15% of the yellow dyestuif of Color Index 1095,are stirred into 90 parts of the above described emulsion clear. Cottonprints prepared from this color emulsion possess good strength,clearness and sharpness of design.

Example 7 540 parts of a predominantly aliphatic hydrocarbon(distillation range 306-394 C.) is emulsified by means of an Eppenbachhomogenizer into 510 parts of a mix consisting of 4 parts of sodiumlignin sulfonate, 45 parts of anhydrous potassium carbonate, 45 parts ofanhydrous sodium carbonate, 70 parts of sodium formaldehyde, 60 parts ofglycerine and 280 parts of water. A creamy, yellowish-white oil-in-wateremulsion results from this procedure.

10 parts of a commercial vat dye paste containing approximately 10% ofthe vat dyestufi of Color Index 1101 are stirred into 90 parts of theabove-prepared emulsion clear. Finished cotton prints of this coloremulsion are clear, bright and strong. They compare very favorably withprints made at the same dyestufi concentration using a conventionalstarch thickener as the vat color carrier.

Example 8 20.8 parts of Orange R powder, Color Index 1217 (preparedaccording to U. S. Patent Reissue No. 21,402) and containing about 18%sodium salt of lignin sulfonic acid, is dispersed by means of anEppenbach mixer into a mix of 24 parts glycerine and 113 parts of water.180 parts of a predominantly aliphatic hydrocarbon (distillation range306-394 C.) are emulsified into the above dispersion. 64 parts of apulverized mix consisting of 18 parts of sodium carbonate, 18 parts ofpotassium carbonate, and 28 parts of sodium formaldehyde sulfoxylate arethen stirred into the above-described emulsion. The product '6 is asmooth, well-bodied, oil-in-water emulsion which, when printed onbleached x 80 cotton cloth and finished in the usual manner for vatprints, produces prints whose brightness and strength compare favorablywith similar prints made at the same vat dye concentration using aconventional starchy-gum as the vat color carrier.

Example 9 45.5 parts of a predominantly aliphatic hydrocarbon solvent(distillation range 306-394" C.) is

' emulsified by means of a high-speed homogenizer into a mix consistingof 30.5 parts water, 2 parts calcium lignin sulfonate and 6 partsglycerine, 16 parts of a pulverized mix consisting of 4.5 parts sodiumcarbonate, 4.5 parts potassium carbonate, and 7 parts sodiumformaldehyde sulfoxylate are then stirred into the above, formulatedoil-inwater emulsion. 88 parts of the resulting wellbodied, tan coloredemulsion are then mixed with 12 parts of an aqueous dispersion of thevat dyestufi Hydron Pink containing 1.8 parts of real dye and theresultant printing paste is printed on unbleached 80 by 80 cotton clothand finished in the conventional manner. The resulting print comparesfavorably in color value, smoothness and sharpness of design with printsmade at the same dye concentration made with a starch gum as the vatcolor carrier.

Example 10 An emulsion clear is prepared as directed in Example 9 exceptthat 2 parts of the chromium salt of lignosulfonic acid are substitutedfor the calcium salt. 12 parts of a commercial vat color pastecontaining about 15% of the Jade Green dyestufi of prototype No. 117 aremixed with 88 parts of the above prepared emulsion and printed on 80 x80 unbleached cotton cloth. Bright smooth prints, which comparefavorably with starchy-gum prints, are obtained in this process.

Example 11 Into an aqueous mix of 1.8 parts sodium lignin sulfonate, 6parts glycerine and 28.5 parts Water are emulsified 43.7 parts ofpredominantly aliphatic hydrocarbon solvent (distillation range 306-394"C.) by means of an homogenizer. To the resultant oil-in-water emulsionare stirred in a pulverized mix consisting of 5 parts sodium carbonate,5 parts potassium carbonate, and 13 parts sodium formaldehydesulfoxylate. When 88 parts of the thickened emulsion thus formed aremixed with 12 parts of a commercial dye paste containing about 15% ofthe green vat dyestuff of prototype No. 117, a colored emulsion isformed which when printed on spun rayon produces good strong prints.

Example 12 A water dispersion is prepared by mixing together 50 parts ofa 10% aqueous suspension of bentonite, 15 parts of glycerine, 5 parts ofa 40% aqueous dispersion of sodium lignin sulfonate and parts water.Into this mix is emulsified by means of a high-speed stirrer 50 parts ofa predominantly aliphatic hydrocarbon of distillation range BOG-394 C. Apulverized mix consisting of 11 parts sodium carbonate, 11 partspotassium carbonate and 17 parts sodium formaldehyde sulfoxylate arethen mixed into the oil-in-water emulsion formed by the foregoingprocedure. The resulting product is a thick, smooth oil-in-wateremulsion clear suitable for vat color printing. 12 parts of a commercialdye paste containing about 17% of the blue vat dyestulf of Color Index 71184' aremix'ed-with 88 parts of the above-formulated emulsion clear andthe color paste so formed is printed on 80 x 80 unbleached cotton clothand the prints finished in the conventional manner. The'finished printscompare favorably in strength and brightness to prints at the same dyeconcentration made with a starchy-gum as the vat color carrier.

Example 13 The procedure of Example 12 is followed except that 50 partsof a 1% aqueous dispersion of sodium alginate are substituted for thebentonite suspension. Prints obtained with this product are strong andbright.

From the foregoing examples, it will be seen that the use and practiceof the present invention has a number of advantages. In many cases,stronger value color'prints are obtained. In general, smoother printsare obtained, particularly in the background or blotch areas. A greatlyreduced solids content is deposited on the fabric durin printing. Thefabrics have a soft hand even before finishing. There are no starches,gums, and the like present to .be washed from the printduring'finishing.

It is also an advantage of the present invention that the printing colorcompositions, so prepared and used, are applicable to substantially allsituations wherein vat dyestufis are printed in fabrics. Particularlyprinting on cotton, rayon, and the like is the invention of particularutility.

Further, because of the nature of the materials, they are more quicklyand easily applied. There is improved opportunity for printing one vatcolor over another to secure mixed shades, and a multiplicity of colors,with the use of only a very few'engraved rolls. Finally since all theformulations are dispersible in water the equipment in which they areused is easily cleaned.

While the illustrative examples given above are concerned with vat dyes,it should be noted that soluble vat dyes may also be used. This may insame cases increase the ease of formulation and application. It may alsoin some cases increase the available color range.

It should be noted, also, that in the above examples neutralized ligninsulfonates have been employed in forming oil-in-water emulsions. Theseare preferred to other types of dispersing and stabilizing agents.Emulsions prepared with these materials are very stable. Among thosesuitable for use are the sodium, potassium, ammonium, calcium,magnesium, and chromium lignin sulfonates. Similarly, lignin-containingproducts from wood wastes, for example some of the distillationconcentrates from which the lower molecular weight fractions areremoved, as shown in U. S. Patent No. 2,201,812, may also be useful.

We claim:

1. A stable color printing composition comprising a. water-insoluble vatdyestuff disseminated through a water-dispersible oil-in-water typeemulsion paste, said paste containing (a) Watersoluble electrolytesincluding alkali metal carbonates and a water-soluble formaldehydesulfoxylate salt (1)) an aqueous bodying material consisting of a liquidhydrocarbon suspended therein as the internal phase, and (c) awatersoluble salt of a lignin sulfonate.

2. A composition according to claim 1 in which the oil-in-water emulsioncomprises as its internal phase a mixture of aliphatic and aromatichydrocarbon oils.

3. A composition accordin to claim 1 in which the oil-in-water emulsioncomprises as its dispersed phase a petroleum distillate solvent having aviscosity not over about five centipoises and a boiling range of IOU-400C.

4. A method of printing with vat colors which comprises printing with aprinting paste composition comprising a water-insoluble vat dyestuffdisseminated through an oil-in-water emulsion, said emulsion containingwater-soluble electrolytes including alkali metal carbonates and awater-soluble reducing agent and a thickener consisting of liquidhydrocarbon suspended therein as the internal phase, and (c) aWater-soluble salt of a lignin sulfonate.

JOSEPH L. BORSTELMAN N FREDERICK FORDEMVT ALT.

REFERENCES CITED The following references are of record in the file ofthis patent:

FOREIGN PATENTS Country Date Germany May 14, 1932 OTHER REFERENCESNumber

1. A STABLE COLOR PRINTING COMPOSITION COMPRISING A WATER-INSOLUBLE VATDYESTUFF DISSEMINATED THROUGH A WATER-DISPERSIBLE OIL-IN-WATER TYPEEMULSION PASTE, SAID PASTE CONTAINING (A) WATERSOLUBLE ELECTROLYTESINCLUDING ALKALI METAL CARBONTES AND A WATER-SOLUBLE FORMALDEHYDESULFOXYLATE SALT (B) AN AQUEOUS BODYING MATERIAL CONSISTING OF A LIQUIDHYDROCARBON SUSPENDED THEREIN AS THE INTERNAL PHASE, AND (C) AWATERSOLUBLE SALT OF A LIGNIN SULFONATE.